Many of the "better" public toilets have coin slots, and it's logical - you want a clean facility, it all costs to maintain. Having said that, I'd rather squat in a bush than go to a public toilet....but being a bloke, that's a sight easier for me than for a woman.
I don't know what womens toilets are like, but blokes ones are notoriously bad. You walk in, then pay the ferryman to row you across the piss lake in the middle of the floor. Cubicle one, pebbledashed up the sides, cubicle two blocked and turds floating to meet you, cubicle three, pee splashed everywhere..........you get the image